code: def __init__(self):
      self.input_indexes = ["A", "C", "D"]
      self.output_indexes = [(0, 0), (0, 1), (1, 0), (1, 1)]
  
file_path: OMLT/tests/test_block.py
imports: import pyomo.environ
  import pytest
  from omlt import OmltBlock
label_desc: Use image node_id 1 to create a new dummy_formulation object from inherited base classes: object with example: obj = dummy_formulation()